/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You under the Apache License, Version 2.0
 * (the "License"); you may not use this file except in compliance with
 * the License.  You may obtain a copy of the License at
 * 
 *      http://www.apache.org/licenses/LICENSE-2.0
 * 
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package org.apache.jasper.tagplugins.jstl.core;

import org.apache.jasper.compiler.tagplugin.TagPlugin;
import org.apache.jasper.compiler.tagplugin.TagPluginContext;

public final class Out implements TagPlugin {

	public void doTag(TagPluginContext ctxt) {

		// these two data member are to indicate
		// whether the corresponding attribute is specified
		boolean hasDefault = false, hasEscapeXml = false;
		hasDefault = ctxt.isAttributeSpecified("default");
		hasEscapeXml = ctxt.isAttributeSpecified("escapeXml");

		// strValName, strEscapeXmlName & strDefName are two variables' name
		// standing for value, escapeXml and default attribute
		String strValName = ctxt.getTemporaryVariableName();
		String strDefName = ctxt.getTemporaryVariableName();
		String strEscapeXmlName = ctxt.getTemporaryVariableName();

		// according to the tag file, the value attribute is mandatory.
		ctxt.generateJavaSource("String " + strValName + " = null;");
		ctxt.generateJavaSource("if(");
		ctxt.generateAttribute("value");
		ctxt.generateJavaSource("!=null){");
		ctxt.generateJavaSource("    " + strValName + " = (");
		ctxt.generateAttribute("value");
		ctxt.generateJavaSource(").toString();");
		ctxt.generateJavaSource("}");

		// initiate the strDefName with null.
		// if the default has been specified, then assign the value to it;
		ctxt.generateJavaSource("String " + strDefName + " = null;\n");
		if (hasDefault) {
			ctxt.generateJavaSource("if(");
			ctxt.generateAttribute("default");
			ctxt.generateJavaSource(" != null){");
			ctxt.generateJavaSource(strDefName + " = (");
			ctxt.generateAttribute("default");
			ctxt.generateJavaSource(").toString();");
			ctxt.generateJavaSource("}");
		}

		// initiate the strEscapeXmlName with true;
		// if the escapeXml is specified, assign the value to it;
		ctxt.generateJavaSource("boolean " + strEscapeXmlName + " = true;");
		if (hasEscapeXml) {
			ctxt.generateJavaSource(strEscapeXmlName
					+ " = Boolean.parseBoolean((");
			ctxt.generateAttribute("default");
			ctxt.generateJavaSource(").toString());");
		}

		// main part.
		ctxt.generateJavaSource("if(null != " + strValName + "){");
		ctxt.generateJavaSource("    if(" + strEscapeXmlName + "){");
		ctxt.generateJavaSource("        " + strValName
				+ " = org.apache.jasper.tagplugins.jstl.Util.escapeXml("
				+ strValName + ");");
		ctxt.generateJavaSource("    }");
		ctxt.generateJavaSource("    out.write(" + strValName + ");");
		ctxt.generateJavaSource("}else{");
		ctxt.generateJavaSource("    if(null != " + strDefName + "){");
		ctxt.generateJavaSource("        if(" + strEscapeXmlName + "){");
		ctxt.generateJavaSource("            " + strDefName
				+ " = org.apache.jasper.tagplugins.jstl.Util.escapeXml("
				+ strDefName + ");");
		ctxt.generateJavaSource("        }");
		ctxt.generateJavaSource("        out.write(" + strDefName + ");");
		ctxt.generateJavaSource("    }else{");
		ctxt.generateBody();
		ctxt.generateJavaSource("    }");
		ctxt.generateJavaSource("}");
	}
}
